The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1887-12-10
Correspondents Baltimore County UniOn.
SCIENTIFIC MISCELLANY.
RAIN AS 4 FERTILIZER.

RAIN As FERTILIZER.
In addition to supplying crops with necessary
moisture, rain has distinct manurial value. At
R6thamsted, the weIl-known farm Of Sir John B.
Lawes, it has been shown that, with an annual
rainfall of little less than thirty two inches each
acre of land receives every year in the rain water
over fourteen pounds Of, pure chlorine, seventeen
pounds Of sulphuric acid, and between two and
three pounds Of ammonia.
STRENGTH OF HEATED METALS.
Some interesting experiments on the effects Of
heating on the strength and ductility of metals
used for machines and structures were recently
made ct the Royal Dockyard, Portsmouth, Eng.
Ali bronzes showed regular, but hot serious, de-
crease of strength and ductility up to certain
point-which is between 800 and 400 degrees for
ordinary gun metals-beyond which the strength
suddenly drops to about one-hal and the ductiIity
vanishes. Phosphor-bronze preserves two-thirds
of its strength and onethird of its duclity up to
500 degrees Fahrenheit and Muntz metal and
pure copper are also fairly satisfactory in these
respects. Wrought iron gains in strength up.to
500 degrees but loses in ductility up to 300 de-
grees, after which it gains. Open hearth steel Is
not affected in strength by temperature of 500
degrees but its ductility is reduced one-half.
COCA CULTURE.
Coca, shrub-growing wild on the mountains
of Peru and Bolivia, is coming into extensive cu-
tivation on account of the rapidly increasing de-
mand for cocaine, the principal alkaloid obtained
from its leaves. The plant resembles the tea
plant, is cultivated in rows like Indian corn, and
in two years attains its full height of five or six
feet, bearing leaves about two inches long, with
white blossoms and red berries. The leaves are
al ksnnoo 81 AZ L.
duced for many years. The peculiar virtues of
coca as Q nerve-stimulant have long been known,
not only to medical men, but to the Peruvian In
dams and miners, who chew the leaves mix ed with
quick-lime, much as tobacco, is ohewed, and who
are thus enabled to resist fatigue to remarkable
degree. 1t was not until 1850, however, that the
active principle isolated, while the great value
of cocaine as local anaesthetic was accidentally
discovered only some three years ago.
NATURES sEED-sowING.
The woody melon-shaped fruit Of the sand box
tree of the West Indies is made into neat box
by saving off the top and scooping out the seeds
and is used in Barbados for holding sand. When,
however, the fruit is allowed to rpen on the tree,
it bursts explosvely, scattering the seeds the
ground. An experimenting naturalist recently
sought to preserve specimen of the fruit by dry
ing carefully, but it exploded with such violence
as to destroy the box containing it.
TINE FOR MARINERS.
The plan Of signalling accurate time from sea-
coasts was first adopted by Great Britain about
thirty years ago. That country now has on its
coasts fourteen time-balls and five other time
signals, and its colonies and dependencies have
twenty six time balls; Germany has seven time
balls France, four time-balls and two other time
signals; Sweden and Norway, Austria Hungary,
Holland with Belgium, and the United States, have
five time-balls each; Denmark has two; Spain
and Portugal, one each; Italy, none.
MISCELLANEOUS
Popular faith is being nailed to hypnotism in
France where all kinds of ailments and peculiari-
ties are now being treated by the mesmerists.-
The cure Of drunkenness has been attempted, by
what is called "suggestion," the patient, while
"under CONTROL" being ordered to abstain from all
intoxicants, and success is said to have been
achieved.
Anlincrease in the demand for mica has resulted
from its use for electrical purposes, and special
machinery has been devised for getting out the
mineral. Electricians usually select the whitest
kinds, some colored micas having so much iron
that their insulating property is affected.
At least 10000 preserved humming birds are
now embraced in the collection in the British
Museum. The finest collection on this side of
the Atlantic, containing about 1000 specimens,
has been presented by Mr.. D. G.. Elliot to the
American Museum of Natural History IN New
York.
A French horticulturist, Count du Buysson,
ensures the growth of seeds so old as to have a
doubtful terminating power by soaking them for
thirty six hours in water containing little guano
or other source of nitrogen.
The Argentine Republic is to have a
weather bureau equipped with fortyl6ve obser-
vatories in different parts of the country.
Some curious results produced by exploding
marked blocks of gun COTTON on fat plates Of
wrought iron have been described by Mr.. G. E.
Monroe. The gun-cotton blocks were placed with
the lettered side down, and the letters stamped in
relief appeared in relief the iron after explosion
while, the other hand, the letters depressed in
.hs ggHa-esssen were also depressed on the iron
plate.
An Oxford meteorological seeks to prove that
the European and American magnetic poles are
coincident with the centres of greatest cold for
the two continents, and that the shifting of the
magnetic poles is due to the series Of astro-
montreal and geological causes which produce the
secular changes in climate.
By means of an air-gun, Prof. c. L. Mees has
found that to drive straws into pine boards and
hickory bark, as is often done by tornadoes, a
velocity of $50 to LIS miles an hour is necessary.
A Berlin company offers electricity for boiling
water, and other heating purposes, as well as for
lighting.